Does carbohydrate-deficient transferrin predict the severity of alcohol withdrawal syndrome?

Alcohol withdrawal often causes severe complications. However, many addicts deny any abuse. Thus, the diagnosis of alcohol abuse frequently becomes difficult. Laboratory parameters are often used to support the diagnosis of alcohol abuse. Furthermore, laboratory parameters should facilitate the prediction of the severity of alcohol withdrawal syndrome (AWS). The most promising laboratory parameter indicating a recent elevated alcohol consumption is carbohydrate-deficient transferrin (CDT). The aim of this study was to examine whether the measurement of CDT at admission can indicate a higher risk for the development of a complicated AWS. The severity of AWS was assessed by the AWS scale, consisting of two subscales for somatic and mental symptoms. CDT was measured by different methods (radioimmunoassay and HPLC). The radioimmunoassay for CDT (CDTect) yielded the best prediction. Our results showed a weak correlation between CDTect and the severity of AWS. However, there were great gender differences. In men, CDTect had the highest positive predictive value for a severe AWS (86.7%), whereas in women mean corpuscular volume was the best predictor (77.8%). However, the sensitivity of CDTect in men (25.5%), as well as mean corpuscular volume in females (29.2%), was too low for a screening test in a general hospital.     

EMS1 gene expression in primary breast cancer: relationship to cyclin D1 and oestrogen receptor expression and patient survival

The EMS1 and CCND1 genes at chromosome 11q13 are amplified in about 15% of primary breast cancers but appear to confer different phenotypes in ER positive and ER negative tumours. Since there are no published data on EMS1 expression in large series of breast cancers we examined the relationship of EMS1 expression with EMS1 gene copy number and expression of mRNAs for cyclin D1 and ER. In a subset of 129 patients, where matched tumour RNA and DNA was available, EMS1 mRNA overexpression was associated predominantly with gene amplification (P = 0.0061), whereas cyclin D1 mRNA overexpression was not (P = 0.3142). In a more extensive series of 351 breast cancers, there was no correlation between cyclin D1 and EMS1 expression in the EMS1 and cyclin D1 overexpressors (P = 0.3503). Although an association between EMS1 mRNA expression and ER positivity was evident (P = 0.0232), when the samples were divided into quartiles of EMS1 or cyclin D1 mRNA expression, the increase in the proportion of ER positive tumours in the ascending EMS1 mRNA quartiles was not statistically significant (P = 0.0951). In marked contrast there was a significant stepwise increase in ER positivity in ascending quartiles of cyclin D1 mRNA (P = 0.030). A potential explanation for this difference was provided by the observation that in ER positive breast cancer cells oestradiol treatment resulted in increased cyclin D1 gene expression but was without effect on EMS1. The relationship between EMS1 expression and clinical outcome was examined in a subset of 234 patients with median follow-up of 74 months. High EMS1 expression was associated with age > 50 years (P = 0.0001), postmenopausal status (P = 0.0008), lymph node negativity (P = 0.019) and an apparent trend for worse prognosis in the ER negative subgroup. These data demonstrate that overexpression of EMS1 mRNA is largely due to EMS1 gene amplification, is independent of cyclin D1 and ER expression and, in contrast to cyclin D1, is not regulated by oestrogen. Independent overexpression of these genes may confer different phenotypes and disease outcomes in breast cancer as has been inferred from recent studies of EMS1 and CCND1 gene amplification.     

Distribution of the perivascular nerve Ca2+ receptor in rat arteries

We recently showed that perivascular sensory nerves of mesenteric branch arteries express a receptor for extracellular Ca2+ (CaR), and reported data indicating that this CaR mediates relaxation induced by physiologic levels of Ca2+. We have now tested whether the perivascular sensory nerve CaR-linked dilator system is a local phenomenon restricted to the mesentery, or is present in other circulations. Vessels from the mesenteric, renal, coronary, and cerebral circulations were studied. Immunocytochemical analysis was performed using anti-CaR and anti-neural cell adhesion molecule (NCAM) antibodies. Wire myography was used to assess contraction and relaxation. Although perivascular nerves of all arteries stained for CaR protein, there were regional differences. A morphometric method used to estimate CaR positive nerve density revealed the following rank order: mesenteric branch artery > basilar artery = renal interlobar artery > main renal trunk artery > left anterior descending coronary artery. Vessels from the mesentery, renal, coronary, and cerebral circulations showed nerve-dependent relaxation in response to electrical field stimulation (EFS) when precontracted with serotonin in the presence of guanethidine. The degree of Ca2+-induced relaxation of mesenteric, renal, and cerebral arteries positively correlated with the magnitude of EFS-induced relaxation. In contrast, coronary arteries contracted at Ca2+ levels between 1.5 and 3 mmol L(-1), and relaxed to a small degree to 5 mmol L(-1) Ca2+. Thus, a functional perivascular sensory nerve CaR-linked dilator system is present to varying degrees in the mesenteric, renal, and cerebral circulations, but only to a very limited extent in the coronary circulation.     

Attenuation of LPA-mediated calcium signaling and inositol polyphosphate production in rat-1 fibroblasts transformed by the v-src oncogene

Alterations in cellular signaling underlie the transforming actions of many oncogenes. The vsrc oncogene tyrosine kinase, pp60vsrc, is known to alter multiple signal transduction pathways, including those involving phosphatidylinositol (PI) metabolism. In this study, we investigated the effects of vsrc-transformation on lysophosphatidic acid (LPA) receptor coupling to intracellular free calcium [Ca2+]i and PI turnover in rat-1 fibroblasts. In normal rat-1 cells, LPA rapidly elevated [Ca2+]i (EC50 = 10nM). In contrast, the ability of LPA to mobilize calcium was markedly attenuated in rat-1-vsrc cells. Further study revealed that the LPA-mediated generation of inositol (1,4,5)P3 and other inositol polyphosphates was also markedly attenuated in the vsrc-transformed cells. Although LPA caused a transient reduction in the level of PI(4,5)P2 in normal rat-1 cells, the agonist elevated the level of PI(4,5)P2 in the vsrc-transformed cells. These findings demonstrate that vsrc-transformation alters the coupling of LPA receptors to PI turnover and calcium signaling in rat-1 cells, and point to G protein-coupled receptor systems as targets for modulation by the vsrc kinase.     

Analysis of regulated exocytosis in adrenal chromaffin cells: insights into NSF/SNAP/SNARE function

In a duplicate study during 1987-1991, 478 24-h duplicate samples from 14 homes for elderly people and 10 homes for youth were investigated for their contents of selected harmful substances. The analyses covered 45 active substances of pesticides, 17 PCB-congeners as well as lead, cadmium, and nitrate contents. Pesticides could be detected only in 15% of the investigated samples. The pesticide contents reached max. 8% of the respective FAO/WHO-limits. As the mean intake of the three most important PCB-congeners (sum of the congeners 138, 153, and 180) values of 0.9 and 1.1 micrograms per day and ration or person, respectively, were found. Also in the worst case the daily PCB intake was below the recommended ADI value of the FDA of 1 microgram/kg of body weight. The daily nutritional intake of lead and cadmium via the investigated daily rations reached about 5.6% and 20% of the Provisionally Tolerably Weekly Intake values of the FAO/WHO. The mean nitrate content of the duplicate portions was 101 mg per day and person (median: 79 mg per day and person). Referred to the median value the WHO limit (3.65 mg/kg body weight and day) was exhausted to about 36%.     

Direction determination in the minus-end-directed kinesin motor ncd

Motor proteins of the kinesin superfamily transport intracellular cargo along microtubules. Although different kinesin proteins share 30-50% amino-acid identity in their motor catalytic cores, some move to the plus end of microtubules whereas others travel in the opposite direction. Crystal structures of the catalytic cores of conventional kinesin (a plus-end-directed motor involved in organelle transport) and ncd (a minus-end-directed motor involved in chromosome segregation) are nearly identical; therefore, the structural basis for their opposite directions of movement is unknown. Here we show that the ncd 'neck' made up of 13 class-specific residues next to the superfamily-conserved catalytic core, is essential for minus-end-directed motility, as mutagenesis of these neck residues reverses the direction of ncd motion. By solving the 2.5 A structure of a functional ncd dimer, we show that the ncd neck (a coiled-coil) differs from the corresponding region in the kinesin neck (an interrupted beta-strand), although both necks interact with similar elements in the catalytic cores. The distinct neck architectures also confer different symmetries to the ncd and kinesin dimers and position these motors with appropriate directional bias on the microtubule.     

Mechanisms of induction of apoptotic DNA fragmentation

PURPOSE: Despite its common use as an indicator of apoptosis, little is known about the mechanisms controlling apoptotic DNA fragmentation in irradiated cells. This review discusses the pathways of chromatin fragmentation, and the role of both nucleases and chromatin structure in this process. DEFINITIONS: DNA fragmentation linked to apoptosis is a combination of cleavage events excising both large DNA fragments within the range 0.4-1.0 Mbp and 50 kbp followed by random cuts within internucleosomal regions (i.e. DNA laddering). The first two cleavage steps can be detected in virtually all apoptotic cells, but DNA laddering is not ubiquitously observed. Endonucleases that mediate this cleavage of chromatin may be classified by substrate specificity, mode of DNA cleavage and their cofactor requirements. CONCLUSIONS: Three major pathways of DNA fragmentation are proposed and discussed: (1) upregulation of endonucleases, (2) their intranuclear/intracellular redistribution and (3) primary changes of chromatin structure.     

Neither dopamine nor dobutamine corrects mesenteric blood flow depression caused by positive end-expiratory pressure in a rat model of acute lung injury

OBJECTIVE: To determine if either dopamine or dobutamine would counteract the deleterious effect that positive end-expiratory pressure (PEEP) has on cardiac output and mesenteric blood flow in a rat model of acute lung injury. DESIGN: Prospective, randomized, controlled trial in a clinically relevant model of acute lung injury. SETTING: Microcirculation research laboratory. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: The animals were anesthetized with pentobarbital (30 mg/kg) by intraperitoneal injection. They underwent tracheostomy, jugular and femoral vein cannulation, femoral artery cannulation, carotid artery thermistor placement, and bowel preparation for in vivo video microscopy. Acute lung injury was created by administering 0.1 N hydrochloric acid (1 mL/kg) via the tracheostomy. Dopamine or dobutamine (2.5 or 12.5 microg/kg/min), followed by two intravenous fluid boluses, was administered to rats ventilated with 5, 10, 15, and 20 cm H2O of PEEP. MEASUREMENTS AND MAIN RESULTS: Mean arterial pressure, thermodilution cardiac output, mesenteric arteriolar diameter, and red blood cell velocity were measured and mesenteric blood flow was calculated. Cardiac output was depressed in rats exposed to 20 cm H2O of PEEP by 32+/-2%. The corresponding values for cardiac output depression at 20 cm H2O of PEEP in rats receiving 2.5 and 12.5 microg/kg/min of dopamine and 2.5 and 12.5 microg/kg/min of dobutamine were 31+/-1%, 21+/-1%, 29+/-0%, and 24+/-2%, respectively. Mesenteric blood flow was depressed in rats ventilated with 20 cm H2O of PEEP by 74+/-3%, while the corresponding values in rats exposed to 20 cm H2O of PEEP and receiving 2.5 or 12.5 microg/kg/min of dopamine or 2.5 or 12.5 microg/kg/min of dobutamine were 86+/-3%, 77+/-3%, 73+/-3%, and 66+/-3%, respectively. Fluid boluses did not correct the deficits in cardiac output or mesenteric blood flow caused by the combination of acute lung injury and PEEP. CONCLUSIONS: The higher doses of dopamine and dobutamine partially, but insignificantly, corrected the cardiac output depression caused by PEEP in a model of acute lung injury. Neither dose of dopamine nor dobutamine was able to improve PEEP-induced mesenteric blood flow depression.     

Hypoxia enhances [3H]noradrenaline release evoked by nicotinic receptor activation from the human neuroblastoma SH-SY5Y

We have used the human sympathetic neuronal line SH-SY5Y to investigate the effects of hypoxia on noradrenaline (NA) release evoked by either raised [K+]o (100 mM) or the nicotinic acetylcholine receptor (nAChR) agonist dimethylphenylpiperazinium iodide (DMPP). NA release was monitored by loading cells with [3H]NA and collecting effluent fractions from perfused cells kept in a sealed perifusion chamber. Cells were challenged twice with either stimulus and release was expressed as that evoked by the second challenge as a fraction of that evoked by the first. K+-evoked release was unaffected by hypoxia (PO2 approximately 30-38 mm Hg), but release evoked by DMPP was significantly increased. For both stimuli, replacement of Ca2+o with 1 mM EGTA abolished NA release. K+-evoked release was also dramatically reduced in the presence of 200 microM Cd2+ to block voltage-gated Ca2+ channels, but DMPP-evoked release was less affected. In hypoxia, DMPP-evoked Cd2+-resistant NA release was dramatically increased. Our findings indicate that hypoxia increases NA release evoked from SH-SY5Y cells in response to nAChR activation by increasing Ca2+ influx through the nAChR pore, or by activating an unidentified Cd2+-resistant Ca2+-influx pathway. As acetylcholine is the endogenous transmitter at sympathetic ganglia, these findings may have important implications for sympathetic activity under hypoxic conditions.     

Cardiac autonomic dysfunction in survivors of acute lymphoblastic leukemia in childhood

Lower levels of baseline ventilatory function have consistently been associated with increased risk of cardiovascular mortality in prospective studies, but the underlying mechanisms are not known. Increased risk of coronary heart disease is associated with higher serum insulin levels. This report examines the relationship between ventilatory function and indirect measures of insulin resistance. Cross-sectional data from 922 nondiabetic participants in the Normative Aging Study were analysed using multiple linear regression models with adjustment for potential confounders. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were examined in relation to indicators of insulin resistance, i.e. fasting insulin and the fasting insulin resistance index (FIRI). Diabetics were excluded because impaired insulin secretion interferes with the validity of these as measures of insulin resistance. Fasting insulin and FIRI were negatively correlated with FVC and FEV1 (all p< 0.001). These associations persisted after adjusting for potential confounders including age, height, body mass index, waist to hip circumference ratio, physical activity, alcohol intake and smoking in separate multiple linear regression models, for both insulin (all p< or =0.0008) and FIRI (all p< or =0.0001). Negative cross-sectional associations between ventilatory function and indirect measures of insulin resistance were found in nondiabetic males. Insulin resistance may contribute to the previously unexplained association between ventilatory function impairment and cardiovascular mortality. Mechanisms underlying the relationship between insulin resistance and decreased ventilatory function remain to be elucidated.